This invention relates to clocks and more particularly to a generic clock with a mechanically driven display, a standard quartz movement and a microcontroller which is programmed to turn mechanically driven features such as clock hands and counters xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d during prescribed intervals of time.
The standard quartz clock with mechanically driven hands has evolved into a low cost, highly accurate time piece. In this type of clock, a quartz crystal oscillator produces a sequence of pulses which drive the hands via a stepper motor and gear train so efficiently that the clock""s accuracy is held to within one minute per month for more than a year. In some clocks of this type counters and other features are driven in the same manner. High production rates and efficient manufacturing practices have reduced the manufacturing cost of the movement of the standard quartz clock to slightly more than the cost of an alkaline xe2x80x9cAAxe2x80x9d battery power supply. The outstanding performance and low cost of the quartz movement have discouraged others from making changes to the quartz movement.
The present invention overcomes the resistance to changes to the mechanical quartz movement by incorporating a feature in the standard quartz movement which provides benefits and features heretofore unavailable. The feature is a low cost programmable microcontroller. The effect of the programmable microcontroller is so remarkable that the efficiency of the standard quartz movement can be substantially increased. Moreover, a common quartz movement can be used for a large variety of novel clocks.
The invention resides in the ability of the low cost programmable microcontroller to act in combination with the standard quartz movement to cause a clock""s mechanical features such as hands and counters to xe2x80x9csleepxe2x80x9d (stop) and xe2x80x9cawakexe2x80x9d (start) during prescribed intervals of time.
The low cost programmable microcontroller (computer chip), responds to the clock""s crystal oscillator by turning xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d the stepper motor which drives the clock""s hands, counters and other features via a gear train. The ability of the microcontroller to turn the stepper motor xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d according to a programmed set of commands provides a number of important benefits.
One benefit is that battery life is substantially increased because current draw is interrupted when the stepper motor is turned xe2x80x9coffxe2x80x9d. Another benefit is that the size of the standard quartz movement can be reduced by replacing its alkaline or NiCad xe2x80x9cAAxe2x80x9d battery with a small low cost lithium battery.
Still yet another benefit is that a lithium battery can be used so efficiently that the battery""s service life is about equal to the life of the clock. Still yet another benefit is that a variety of novel clocks are derived with a common standard quartz clock movement by merely changing displays and re-programming the microcontroller. For example, the microcontroller can be re-programmed to drive an hour or minute hand shaft of an existing clock with the standard -quartz movement to produce a 12-hour clock, a 7-day clock, an ocean tide clock, etc.
A further benefit is that a programmable microcontoller is lower in cost than unique gear trains because of investment savings, inventory savings and higher production rates. Still yet another benefit is that ancillary features, such as alarms, beeps, snooze buttons and dial lamps can be easily incorporated by simple modifications to microcontroller software.
In employing the teaching of the present invention, a plurality of alternate constructions can be adopted to achieve the desired results and capabilities. In this disclosure, some alternate constructions are discussed. However, these embodiments are intended as examples, and should not be considered as limiting.
Further objects, benefits and features of the invention will become apparent from the ensuing detailed description and drawings which illustrate and describe the invention. The best mode which is contemplated in practicing the invention together with the manner of using the invention are disclosed and the property in which exclusive rights are claimed is set forth in each of a series of numbered claims at the conclusion of the detailed description.